Gelatin is made of animal bones, cartilage, and skin. It is a common ingredient in soups, broths, sauces, gummy candies, marshmallows, cosmetics, and medications. This common thickening and gelling agent is an animal-based product that contains high levels of protein.

How reliable is this? Partial abstinence is an American thing.

I’ve been told by a priest that gelatin used for medication, like capsules, liquid, or chewable does not break abstinence or fast including Eucharistic fast if taking it cannot be delayed. In these cases, it is a vehicle to convey medication to the body, not a food or drink. Nobody eats a Z-pack of Zithromycin, drinks Mucinex, or eats omeprazole gel tabs for GERD!
 

I’d class vitamins with medicine. You don’t eat vitamins. Why does anyone take vitamins or minerals?  Why would anyone take them except as medicinally?  The medicine needn’t be prescribed by a doctor. Example, acetaminophen is over the counter and comes in gel caps, tablets, liquid which often contains gelatin. I take Dailyone Multivitamin + Minerals for senior women, 60+ It’s in a gel cap. I take one in the morning with a blood pressure tablet. I do not eat them! Bite it by accident and it tastes just terrible!
No one would serve Tylenol and Multivitamin as a side dish or condiment with a meal!